PCB Fabrication Tolerances
Adhere to our tolerance guidelines to ensure the best results for your printed circuit boards. They provide enough variation for us to manufacture your board – and for it to work properly in your application.
Copper to Edge of Printed Circuit Board
Minimum of 0.007″ (outer layers) and 0.015″ for inner layers (0.020″ preferred for inner layers). For scoring, minimum of .015 for outer layers and .020 for inner layers.
Pad Size/Annular Ring
Pad size should be at least + 0.008″ over finished hole size for vias and + 0.012″ over finished hole size for component holes. This means the annular ring (radius of the pad) should be at least .004″ for vias and a minimum of 0.006″ for component holes. VIPPO process allows + 0.006” (0.003” each side)
Hole Size
Our minimum finished hole size is 0.004″ laser, 0.005″ mechanical. Call your salesperson if you required a finished hole size less than 0.004″.
If your hole tolerances are zero, then Imagineering will assume that you are OK with our default hole tolerance.
- +/- 0.004″ Standard Spec (applies to holes up to .125″, larger holes will be routed
- +/- 0.003″ Standard Spec
- +/- 0.002″ press fit holes
Printed Circuit Board Thickness
Boards below 0.04” thick +/-0.004”
Boards above 0.04” thick +/-10%
Minimum Board Thickness
Thickness | Default File Review Req. |
---|---|
2-Layer .010″ | .010″ |
4-Layer .020 | .015″ |
6-Layer .031″ | .025″ |
8-Layer .04″ | .031″ |
10-Layer .062″ | .040″ |
Rout (Board Outline and Internal Cutouts)
The board size Tolerances on Standard Spec defined boards is +/- 0.005″
Note: We rout to your board size using the center of the board outline from the outside.
Copper Trace Width/Spacing
Copper spacing is the minimum air gap between any two adjacent copper features. Trace width is the minimum width of a copper feature, usually traces. A premium is charged for trace width/spacing less than .005″.
- For 0.5 oz. finished copper weight: the minimum trace width/space is 0.003″
- For 1 oz. finished copper weight: the minimum trace width/space is 0.004″
- For 2 oz. finished copper weight: the minimum trace width/space is 0.006″
- For 3 oz. finished copper weight: the minimum trace width/space is 0.009”
- For 4 oz. finished copper weight: the minimum trace width/space is 0.012″
Trace Width and Air Gap
Trace/Space smaller than 0.01”, the tolerance is +/-0.001”
Trace/Space larger than 0.01”, the tolerance is +/-0.0015”
Soldermask Swell
This is the expansion of mask relief over pad area. Our minimum is 0.004″ over pad dimension or 0.002″ each side. Imagineering will modify files to meet the minimum dimension, unless requested otherwise.